The packaging art is replete with various devices utilized in the packaging of condiments.
U.S. Pat. No. 3,578,778 teaches employment of a rotating filling wheel or drum having a plurality of cam actuated trap chambers or traps mounted on the drum periphery and which drum holds the material to be packaged. Each trap fills with material, isolates one or more units of material and discharges material units into synchronized individual packets or containers to be filled. While a marked advance over the prior art, the trap operations have required many moving parts.
U.S. Pat. No. 3,631,903, over which this invention marks an improvement, resides around the concept of maintaining a supply of fluid material to be packaged in a rotatable drum, rotating the drum at some uniform speed in a constant direction, and simultaneously rotating a set of "traps", i.e., metering devices or trap chambers, which are arranged in a circular configuration and which are connected to and which rotate with the drum. Each trap provides an elongated, non-linear, material flow path between an inlet and outlet and in the embodiments disclosed in the patent such path is of helical shape. At a filling station each trap is positioned so that the material to be packaged is drawn from the drum through the trap inlet and so as to locate itself at one end of the helical path. As the valve rotates around the drum axis all material in excess of a unit of material is discharged through the inlet and the rotation causes the unit to move along the helical path and approach the trap outlet. As the trap reaches a separate discharge station, the unit of material reaches the end of its helical path and is discharged in synchronism with a packet or other container to be filled, mating with the trap outlet. Two or more such helical paths and two or more units of material may be discharged simultaneously.
U.S. Pat. No. 3,923,084 teaches retention of the basic filling drum technology of U.S. Pat. No. 3,631,903 including the use of spiral traps which meter a unit of material to be dispensed. The patent also teaches various improvements in feeding strip paper packets into position to receive the material from the drum.
Each of the foregoing apparatus described in these patents provided improvement in the packaging art, however, the utilization of such apparatus has revealed the need for changes. Specifically, the apparatus are somewhat limited in the materials which they can dispense and they cannot dispense plural products, i.e. packets with more than one product inside.